AU713539B2

AU713539B2 - Mobile hand-held equipment with biosensor

Info

Publication number: AU713539B2
Application number: AU47145/96A
Authority: AU
Inventors: Norbert Klimes; Jurgen Nentwig; Dorothea Pfeiffer; Frieder Scheller; Jan Szeponik
Original assignee: BST Bio Sensor Tech GmbH
Current assignee: ABT Advanced Bioanalytical Technology GmbH
Priority date: 1995-07-10
Filing date: 1996-01-26
Publication date: 1999-12-02
Anticipated expiration: 2016-01-26
Also published as: AU4714596A; CN1205478C; EP0842421A1; ES2251726T3; DE29511566U1; HK1017425A1; DE19680548D2; DE19680548B4; ATE306665T1; WO1997003355A1; CN1194035A; US6171238B1; EP0842421B1

Abstract

The invention pertains to a portable hand device with biosensor for the investigation of biological fluids such as whole blood, liquor, urine and serum. It is characterized by a securely fixed electrode, which is covered by a replaceable biomembrane, as reservoir bag containing system solution and a waste bag, a pump, a tube transport system, an operating lever with a valve function, three operating elements, a display, and a control unit signal capture and overall procedure.

Description

Mobile hand-held equipment with biosensor Description The invention concerns a hand-held equipment for the examination of biological liquids such as whole blood, liquor, urine and serum with the aid of electrochemical biosensors without costly preceding analyses being carried out.

For a fairly long time biosensors have been applied as sensitive and selective detection methods in analyses, in particular of medical diagnostics. For this purpose, respective biosensors are installed in analysers which allow to carry out a fast, inexpensive and notably proper examination of the respective parameters in central laboratories where many samples have to be examined. This requires, as a rule, a sample throughput of 80 180/h.

The analysers are based on various principles. For the most part, they are operated with a continuous air segmented flow of the respective, highly diluted laboratory samples, i.e. this method requires the preparation of the solutions to be examined whole blood) with a dilution of the analysis material being required. It is very costly to analyse individual samples by means of this equipment as the efficiency of analysers becomes effective only in the case of a high number of samples being examined (ESAT 6660 and ECA 180 from PrUfgerate-Werk Medingen GmbH, EBIO (Eppendorf from Eppendorf-Netheler-Hinz GmbH).

Furthermore, there are instructions known to measure individual samples also without preceding analyses being carried out which, however, are very immovable owing to a high integrated measuring comfort, thus being unsuited for a local application (YSI 2300 STAT of YSI Incorporated and STAT Profile PLUS of NOVA BIOPMEDICAL GmbH).

From EP-A-O 520 443 a portable sensor equipment is known which consists of a waste collector, liquid canals and intakes and an electrochemical sensor in a case and an external calibration unit.

For the time being, commercialized mobile systems with integrated biosensors are too expensive owing to the high measuring comfort (internal calibration), require too much maintenance and are operated with too long transport ways for the sample to be measured. For this reason, in addition to a comparatively high price, delays and pollution will result which have detrimental effects on the quality of analysing.

All measuring systems applied locally to determine parameters such as glucose and lactate are at present based on nonreusable consumables (test strips, photometric; strip electrode, amperometric). Thus the analysis is determined by the price of the test strip and the test strip is not calibratable as it may be used just once.

That is why it was the task of the invention to provide a technical solution for implementing a locally applicable equipment for the examination of blood, urine, liquor without preceding analyses being carried out and a re-usable biosensor which is marked by a low price and also lowest maintenance costs.

The task will be solved by the construction of a hand-held equipment.

The hand-held equipment consists of a rigidly anchored electrode which is covered by a replaceable biodiaphragm, equipped with a system solution supply bag and a waste bag, a pump, a hose transport system, an operating lever with valve function, three operating elements, a display and a control unit for signal recording and the whole process. The equipment works with a temperature compensation. Thus, modified sensitivities of the biosensor are compensated through variations of the ambient temperature in the range between 150C and 35°C on the basis of a signal-temperature function.

Welded PE foils are preferentially used for the system solution and the waste, with the storage volume totalling approx. 1/3 and the waste volume approx. 2/3 of the total volume. In a preferential variant of execution the two bags are welded with each other. They are arranged one above the other and disposed jointly upon consumption of the buffer stock. The bag is opened when being installed the hand-held equipment through a hollow needle. When putting in a new supply bag the second half of the PE bag will be empty. In the same way as the stock will be consumed for purifying the measuring cell the waste bag will be filled. After having consumed the system solution completely the whole bag will be disposed.

The rigidly anchored electrode is a Pt-Ag/AgCl electrode of a CLARK electrode type. By combining it with a ready-made biodiaphragm by placing simply this the electrode is converted into a biosensor which may register various substances in accordance with the biomolecule used.

To execute a measurement the operating lever will be changed from idle position B to position A thus opening the flow system. By turning the pump into position I the electrode will be put into the state ready for measurement with the system solution in front of it having been sucked off.

The sample to be analysed will be supplied with adjusting the freshly taken sample in a capillary tube to the sample opening of the hand-held equipment which is directly above the biosensor. Subsequently the pump is set in position II and the sample to be measured is transported by it in front of the biosensor. After effecting the measurement the result will be shown on the display and the operator will be requested to purify the system. The capillary tube is taken off by the user.

By putting back the operating lever to position B the purification system is again closed. Purification itself is effected by turning the pump slowly until "ready for use" will appear on the display which is regarded to be a confirmation that the purification is completed and the pump will be in position III.

A hose pump is preferentially used as pump.

he three operating elements will be responsible for the I lowing functions: Bl: on/off B2: menu functions B3: set key Power supply will be possible through an internal 9V accumulator as well as an external solar cell or a supply unit.

Depending on the biomolecule used a biodiaphragm has a limited lifetime which totals, in general, 10 to 30 days. The user will be shown the expiry of lifetime on the display. Upon expiry of its service life the biodiaphragm will be replaced by a new one.

The biodiaphragm is replaced by unlocking the respective sealing cap, taking off the worn-out diaphragm and simply placing a new diaphragm. By the information on the display the user will be informed on the steps necessary to take until the new diaphragm will be operative.

Signal recording and the whole process are controlled through a control unit. The whole process involves the beginning of signal recording (start), the end of signal recording, filing and storing of measured values, the calibration of the equipment and display information for the operator as regards the steps.

The hand-held equipment in conformity with the invention allows to carry out a minimum of 300 measurements without replacing the supply bag. A special advantage is that the equipment is usable in a temperature range between 15°C and independent of its place and time of use. In addition, the weight of the equipment is less than 500 g.

The invention is explained in greater detail by means of the following examples of execution and drawings.

Fig. 1 Overall view of the hand-held equipment Fig. 2 Basic diagram of the equipment and arrangement of the supply and waste bags Fig. 3 View of electrode arrangement and representation of the replacement of the biodiaphragm The hand-held equipment in conformity with Fig 1 serves the examination of whole blood, liquor, tissue fluid, urine, serum, plasma, food samples as well as water samples as regards metabolites such as e.g. glucose, lactate; yet also nutrients and products of food and fermentation industries such as e.g.

lactose, ascorbic acid, malic acid and various amino acids.

In Figs. 1,2 and 3 the principle process of such a measurement is demonstrated. With the operating lever 8 opened (A 10) the buffer segment is put in position I by pump 4, a hollow needle with the sample to be analysed is put into opening 24, pump 4 is put in position II and thus positioned in sample canal 25 above the biosensor 33 to start measurement. After completing measurement the measured value will be shown on the display and the operator is requested to purify the system. For this purpose, the hollow sample needle is taken from opening 24, the operating lever 8 is put in position B (9) and by turning pump 4 system solution is moved from the supply bag 19 through the hose transport system 21 into the waste bag.

This contact of the biosensor with the buffer solution results in the purification of the sensor. The operator is informed on the termination of the purification by "ready for use" on display 1. Now, the pump is again put into idle position III Thus, the hand-held equipment will be again ready for measuring and the following measurement will be effected according to the same scheme.

According to Fig. 3 the biodiaphragm may be again replaced upon expiry of the lifetime of a biomembrane (which is shown the operator on display To this end, the operating lever 8 will be drawn upwards through spring 17 and turned upwards by 90 Thus, it is possible to swing open by 90 the measuring cell cover 28 on axis 26 by releasing the fixing device 29. It is now possible to take off the worn-out biodiaphragm 32 and to put a new one on electrode 33 which is equipped with a rubber joint 34. Thereupon the measuring cell cover will be again swung down, stopped in 29 and the operating lever will be again put in position B Thus the flow system will be again closed and by turning the pump system solution will be put on the biosensor for conditioning.

Reference marks: 1 display 2 plotting unit 3 connection for solar cell or supply unit 4 pump pump position I 6 pump position II 7 pump position III 8 operating lever 9 operating lever position B operating lever position A 11 measuring cell with biosensor 12 operating element B1 13 operating element B2 14 operating element B3 case 16 accumulator 17 spring for operating lever waste bag t b 19 supply bag hollow needle (connection between hose system, waste or supply bags) 21 hose system 22 seal for waste bag 23 seal for supply bag 24 sample opening sample canal 26 axis 27 connection with the hose transport system (connection between sample canal and hose) 28 measuring cell cover 29 fixing device of the measuring cell cover measuring cell bottom 31 connections for electrodes 32 biodiaphragm 33 electrode 34 electrode seal

Claims

1. Mobile hand-held equipment with biosensor, in particular for the local determination of original biological solutions, the said equipment including an amperometric biosensor, a measuring cell, supply and waste bags for fresh and waste system solution, a pump, a hose transport system, a sample opening and a sample canal, an operating lever with valve function, equipment for replacing diaphragms, a display, three operating elements, a 9V accumulator, a solar cell or supply unit connection, a plotting unit for signal recording and the whole measuring process and a case.

2. Mobile hand-held equipment with biosensor according to claim 1, wherein the 9*0000 biosensor is arranged directly below the sample opening. 009

3. Mobile hand-held equipment with biosensor according to claim 1 or claim 2, 1 wherein the pump used is operated by hand and without using electric energy. S4. Mobile hand-held equipment with biosensor according to any one of claims 1 o .i to 3, wherein welded PE foil is used for the supply and the respective waste bags the two bags are welded with each other, arranged one above the other and will be jointle disposed after the buffer stock will have been consumed. Mobile hand-held equipment with biosensor according to any one of claims 1 to 4, wherein the power supply of the electrode may be effected through a chargeable accumulator as well as a solar cell or a supply unit. 7

6. Mobile hand-held equipment with biosensor according to any one of claims 1 to 5, wherein the weight of the equipment is less than 500g.

7. Mobile hand-held equipment substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings. DATED THIS 2 4 TH DAY OF SEPTEMBER 1999. BST BIO SENSOR TECHNOLOGIE GmbH By their Patent Attorneys LORD COMPANY PERTH, WESTERN AUSTRALIA.

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